Soy products protect against lung cancer

Eating a lot of tofu, as well as other unfermented soy products, may protect people against lung cancer, according to a recent Chinese study.

Reviewing past studies, the researchers found that 23% of the time, people who ate the most soy products seemed to have less risk of getting lung cancer.

The researchers were able to make use of 11 studies, some of which followed people for a decade or longer.

Matthew Schabath, a researcher at the Moffitt Cancer Center in Tampa, Florida, whose study the researchers used, said he believed the link between lung cancer and soy intake was complicated.

He said that researchers had wondered for decades why there seemed to be a connection between dietary soy intake and beneficial effects, and that the effect could be due to more than just one nutrient.

Scientists working with soy have already shown that isoflavones, compounds found in abundance in the plant's cells, slow cancer growth in laboratories.

But there is a lack of real-life situations in which such compounds seem to affect people's lives, prompting the Chinese researchers to make a review of available medical literature.

They were able to arrive at the statistic of a 23% lowered risk after pooling the results of all the relevant studies.

In the process, foods that used fermented soy, such as tempeh, miso, and soy sauce, were all eliminated as being statistically irrelevant.

Only unfermented soy products, such as tofu and soy milk, seemed to have an effect.

According to the American Cancer Society, about 8% of men will develop lung cancer at some point, while 6% of women will get the disease.

The new findings, published in the American Journal of Clinical Nutrition, come with several caveats, however.

Lead researcher Wan-Shui Yang from the Shanghai Jiaotong University School of Medicine said that the results were very preliminary, and that the lowered percentages of lung cancer were only found among people who never smoked, among women, and among East Asian populations.

Schabath said that there was no magic pill containing beneficial soy compounds to prevent lung cancer.

He said that the fact that scientists could not make such a pill just showed the complexity of the problem, and that if people wanted to cut their risk of lung cancer they should stop smoking.